July 23 (Reuters) - Major stock markets in the Gulf were mixed in early trade on Thursday, as investors weighed escalating regional tensions and a raft of corporate earnings announcements.

The U.S. military said on Wednesday it had carried out another round of strikes on Iran at President Donald Trump's direction, marking a 12th consecutive night of American attacks.

Iran's Revolutionary Guards said an oil tanker caught fire after an explosion while attempting to navigate what they described as a mined route in the southern Strait of Hormuz, near the coast of Oman, while two other tankers turned back.

Saudi Arabia's benchmark index .TASI eased 0.1%, hit by a 0.9% fall in the country's biggest lender Saudi National Bank 1180.SE.

However, oil major Saudi Aramco 2222.SE gained 0.5%.

Tensions were further heightened after the Iran-aligned Houthis said on Thursday they had attacked two Saudi oil tankers in the Bab el-Mandeb Strait, raising concerns over a potential threat to another key global energy shipping route alongside the Strait of Hormuz.

The Qatari index .QSI lost 0.3%, with petrochemical maker Industries Qatar IQCD.QA dropping 1.2%.

Dubai's main share index .DFMGI gained 0.6%, led by a 2.9% rise in top lender Emirates NBD ENBD.DU. The lender reported second-quarter profit that was broadly flat from the previous quarter, as asset growth and margins remained resilient in its first full-quarter results since the onset of the Iran war.

In Abu Dhabi, the index .FTFADGI rose 0.7%, buoyed by a 4.1% rise in the United Arab Emirates' biggest lender First Abu Dhabi Bank (FAB) FAB.AD following a rise in quarterly earnings.

FAB's net profit for the three months ended June 30 rose to 5.72 billion dirhams ($1.56 billion), from 5.51 billion dirhams a year earlier.